Seasonal atmospheric characteristics in a swine finishing barn equipped with a continuous pit recirculation system using aerobically treated manure

Objective: This study was conducted to determine the seasonal characteristics of odorous material emissions from a swine finishing barn equipped with a continuous pit recirculation system (CPRS) using aerobically treated manure.Methods: The CPRS consists of an aerobic manure treatment process and a pit recirculation system, where the solid fraction is separated and composted. The aerated liquid fraction (290.0%±21.0% per day of total stored pig slurry) is continuously recirculated to the top of the slurry in the pit. Four confinement pig barns in three piggery farms were used: two were equipped with CPRS, and the other two operated a slurry pit under the slatted floor across all seasons.Results: The indoor, exhaust, and outside odor intensities were significantly lower in the CPRS group than in the control group (p2, NH3, and H2S contents of the CPRS group were significantly lower than those of the control group (p3, H2S, methyl mercaptan, dimethyl disulfide, trimethylamine, phenol, indole, and skatole levels were significantly lower in the CPRS group than in the control group (p